Project Summary/Abstract Aggressive behavior that co-occurs with mental disorders has been associated with distinct trajectories, manifestations and severity of mental illness, suggesting a distinct etiological process relative to when the disorder is expressed without aggression. Thus, one key to cutting across diagnostic boundaries in the understanding of underlying psychopathological processes is to investigate the biobehavioral mechanisms behind transdiagnostic symptom dimensions like aggression. As such, the current proposal will test a process model of emotional aggression that implicates the functional interplay of biobehavioral systems under at least two of the domains in NIMH?s Research Domain Criteria (RDoc), Negative Valence and Cognitive systems. Given the increasing influence of RDoC in potential shifts in conceptualization of psychopathology, the RDoC mapping of aggression will ensure that processes that propel aggressive behavior across various forms of psychopathology are given due influence in terms of research, intervention and prognostic judgments. The proposed project involves three aims across two sites that leverage availability of samples that vary on aggression proneness (selected community sample and existing pool of high-risk participants) to reveal causal connections between affective and cognitive brain systems and test specific predictions from the model. Event- related brain potential and startle measures of cognition and emotion will be used to obtain temporally precise indices of brain responses to incoming stimuli and how these relate to behavior. The first aim will experimentally identify whether acute and sustained threat exposure actually alter cognitive systems, specifically brain circuits involved in attentional alerting and cognitive inhibition, respectively, among persons with varying levels of aggression proneness. The second aim will examine the extent to which these threat- related alterations of attention or cognitive control actually predict aggressive behavior in the lab and real life instances subsequent to the measurement of these processes. The third aim will explore whether depression symptoms relate to distinct neurocognitive profiles depending on the level of aggression present. The data from this project can be used to further work that compares syndromes on the presence or absence of aggression to identify biological mechanisms that explain differential trajectories in mental illness, a key step to developing treatments that reflect more general processes in psychopathology.